The objectives of this research are to characterize the changes in hormone-stimulated lipolysis which occur following adrenalectomy and to determine the site of the biochemical lesion which results. To accomplish this, various steps in the lipolytic process will be measured. Adenylate cyclase, phosphodiesterase, and protein kinase will be assayed by radioactive techniques. Cyclic AMP levels will be determined by a protein binding assay. Glycogen phosphorylase will be assayed by a fluorometric assay. Similar type studies will be carried out with tissue from "old" rats. If possible, cyclic AMP levels in human urine and plasma will be correlated with animal data.